

His name is closely tied to leading figures and projects of the Czech music scene across various genres. He contributes to albums, concerts, and music videos either personally as a cellist or from the position of a manager representing the premium ensembles Unique Orchestra and Unique Quartet. The artists he collaborates with in this manner include Ewa Farna, Ben Cristovao, NobodyListen, Vladimír 518, DJ Wich, Nik Tendo, Lenny, Pokáč, Jan Cina, Lenka Dusilová, Michal Pavlíček, Aneta Langerová, Klára Vytisková, Svojost, Jan Smigmator, Radůza, and many others; in the past, this also included Karel Gott. Among bands, he works with Chinaski, Mirai, Lucie, Vesna, Cocotte Minutte, Lake Malawi, and many more. He also collaborates closely with top music producers—such as Jan Steinsdörfer, Jakub Strach (NobodyListen), Ondřej Fiedler, Viliam Béreš, Lukáš Chromek, and Igor Ochepovský.
Currently, one of his main projects is the Unique Orchestra, which he founded in 2020. This ultimate orchestra for the contemporary scene leaves classical music to traditional ensembles and specializes purely in pop, rock, jazz, R&B, hip-hop, and electronic music. While for classical orchestras these genres are often just an occasional detour, for the Unique Orchestra, they represent its natural environment. As a result, the ensemble offers maximum authenticity and a compelling sound in these styles. Moreover, it stands out with its sophisticated visual presentation and captivating, raw energy on stage. That is also why a number of the aforementioned artists regularly harness its power for their live shows. The project organically built upon the success of the multi-genre string ensemble Unique Quartet, which Šimon founded back in 2016 and which continues to record and perform with top-tier artists of the Czech and Slovak scenes.
He is also successfully expanding his activities into the role of a producer. For instance, he is behind the popular and highly attended music project The Little Prince Recital (Recitál Malý princ) featuring Jan Cina. Furthermore, this performance holds a strong personal significance for him, as the music was composed by his father, the respected composer Kryštof Marek. This intergenerational dialogue gains another dimension on stage through the involvement of Šimon's own ensembles—the musical accompaniment for the performance is provided by the Unique Quartet, which expands into the full Unique Orchestra for larger shows. Šimon successfully transformed this originally theatrical project into an attractive concert version, thereby confirming his ability to innovate, develop, and manage complex formats.
Alongside his leadership, producing, and managerial activities, he has also been a member of the string SVA Trio (consisting of Alexey Aslamas – violin, Vladan Malinjak – viola, Šimon Marek – cello) since 2020. With this trio, he focuses purely on original music, which resulted in the release of their debut album Urban Fusions in the autumn of 2021, to be followed by a new record this year. Furthermore, he is actively involved in the pop De Facto Quartet. In the past, he was also a part of the Prague jazz-fusion formation Ochepovsky Project and the experimental band Talaqpo.
He grounds his wide genre span and musical vision in a solid foundation of classical education. He holds a master's degree in cello performance from the Academy of Performing Arts in Prague (class of Mikael Ericsson) and is a graduate of the Jaroslav Ježek Conservatory (class of Jan Keller), where, in addition to his main instrument, he also studied composition under Professor Karel Růžička.